My backlight turns off when set to more than lowest level

Hi there,

When suddenly my screen remained black when opening my MacBook I first thought my MacBook had died - but then found out it's (just) the backlight. System works with external screen. Odd: When I open the MacBook with my screen set to lowest brightness then the screen stays on. And the screen itself still works - I can see it when shining light through the Apple logo.

And - yes, I already tried to

- Reset PRAM

- Reset SMC

I googled and found hints it could be the inverter and/or cable. However, there's no flickering when changing the screen's angle - does that rule out the cable?

Any help will be appreciated.

Thanks!

>> Update: Today (2 days after initial posting) I could set the brightness to level 2 or even 3 for a little while. And one more thing: The keyboard lights won't work anymore either. They come up for a few seconds and then gone and will not resond to setting the brightness level with Function keys F5 or F6.